OFFIFICIALS HAVE IDENTIFIED THE SHOOTER.. IN THE SHOOTING DEATH OF A TEENAGER. POLICE SAY 19- YEAR-OLD JOHARRI WALKER.. IS WANTED IN THE KILLING..OF 16- YEAR-OLD STEFAN JOHNSON. THE SHOOTING HAPPENED ON MARTIN DRIVE IN MARRERO.. YESTERDAY AFTERNOON. THE TEEN DIED AT THE HOSPIAL. EMERGENCY ROOM PHYSICIANS WERE ABLE TO REVIVE HIM.. BUT HE DIED FEWER THAN 24 HOURS AFTER BEING REVIVED.